Actually, Chris has already revealed that Russel is falsely accused of rape during the marathon. Chris also revealed that is his fault that Russel has been accused by the mentors and that he isn't brave enough to confront them.
As to Russel being bisexual, IDK, he's writing doesn't give us any hints, but from what I heard from the Patreo targets, he will have a route eventually. So, yeah, maybe later we will see his bisexuality in action.